Eat Watermelon and save your heart

Watermelon is good for the heart? Yes, and it is also is being touted by some as a "natural viagra". These two issues are inter-related and will be addressed later in the post. This post was prompted by a news item on the BBC website which found that low fat, low carb, and mediterranean diets can reduce the size of plaques in our arteries. The effect was small, only a 5% volume reduction and probably of little value to those with serious coronary plague, at least in the short term. Keep in mind that over the long term that ongoing 5% reduction, if sustained over many years, could be critical in preventing a heart attack.

Have a look at the image on the left. It shows how plague can build up to such high levels it can block the artery and induce occlusive strokes or a heart attack. The typical advice we receive is that we must be carefully control our diet, exercise regularly, and eat heart healthy foods. What is not often mentioned directly relates to benefits of watermelon and other foods that provide a substrate which is essential to maintaining cardiovascular health.



Let's first look at the implications of that BBC news release. If all these diets can reduce atherosclerotic lesions then clearly the diets are not the principal causative factor. It could simply be that those people in this study paid more attention to their diet and so had improved cardiovascular health not so much because of a specific diet but because they were including more antioxidant rich foods in their diet. Antioxidants are very important in combating heart disease because there is now substantial evidence that the initiating events of atherosclerosis involve an inflammatory response that potentiates plague formation. I don't know if this is the reason for the result but I find it instructive that in this study the benefits of the 3 diets were equal.

When checking some background data relevant to the BBC news release I came across this abstract. The final statement is:

Further, we found a close relation between atherosclerosis and endothelial senescence and that NO can prevent it, especially in a diabetic model. Taken together, regression of atherosclerosis can be achieved by not only regulation of various risk factors but regulation of the cross-talk of NO and free radicals.

NO is nitric oxide. Innumerable studies have highlighted the importance of maintaining adequate levels of nitric oxide in sustaining cardiovascular health. Nitric oxide is very important in modulating oxidation events and more particularly in maintaining vascular flexibility. "Stiff" arteries are more inclined to be damaged. The reason for this could be simple physics. Arterial walls are being constantly damaged but larger particles may induce subtle tears. A more flexible artery may bend with the blow thereby alleviating the damage to the wall. I'm speculating troops, undoubtedly the picture is much more complex than that.

Statin drugs have been one of the most important medical breakthroughs. We still do not fully understand exactly how statin drugs provide the benefits but we do know it is much more than simply reducing cholesterol.  There is even evidence that statin drugs can reduce the risk of dementia. Not so surprising because there is a strong relationship between cardiovascular health and cerebral health. Do statin drugs impact on nitric oxide production? I found this tantalising little study which concluded:

Thus statins improve nitric oxide production and vasodilatation. In a recent work in the hypercholesterolemic Watanabe rabbit, we have demonstrated that the combination of arginine with a statin, namely atorvastatin, significantly hinders the spreading of atherosclerotic plaques as compared with monotherapies. Such association of a nutriment and a drug open a new area of therapeutic strategy.

So what does all this have to do with watermelon? The casual chain goes like this:

• Watermelon is rich is citrulline.
• Citrulline is important in maintaining arginine levels.
• Arginine is an essential precursor for nitric oxide production. 

For more information read this link.

We've all heard about viagra and now some are touting watermelon as a substitute. The reason for this is because viagra was initially intended to be a drug for cardiovascular conditions because it upregulates the production of nitric oxide. However it did not act on the large coronary arteries but instead had a significant impact on the smaller arteries. By increasing vasodilation nitric oxide is important for erectile function.

Another striking benefit of watermelon is that it has large amounts of lycopene. Lycopene is a carotenoid that appears to confer protection against prostate cancer. If you read this link you will find that watermelon is superior to tomatoes in providing this important nutrient. Additionally that link asserts that lycopene tissue levels correlate with the risk of heart disease. The higher the level, the lower the risk. So eat your watermelon, it is not only good for your heart but also reduces cancer risk. Apart from that, it is delicious.